43qt uP~Date
Well, I use mine based inside my Honda CRV's rear passenger side door area.
Mine too draws the 5.5 Amp-Hours:
I get about 2.8 to 3.5 days of 80 degree temps using my trailer deep cell battery. I get 5+ days when temps are 40 degrees or there abouts. Never did get a low battery when the temps were below zero to 60's at the first Glyphs gathering.
I did have to run heavy duty # 10 gauge 20amp fused wire direct from my battery as an extension as the internal thin wire of the pre~wired trailer wouldn't handle the initial surge the refrigerator takes.
I also have run #10 gauge wire under the Honda CRV to the rear seat area for the use of the refrigerator while on the road. The same problem of wire size wouldn't keep the unit going with the internal wiring.
Before I figured out that the Current Resistance Drop as related to the wire size and length was an issue I did have some gnashing of teeth.

All works fine now and I would recommend an indoor

This is the Wireless Temp sensor I have Acurite Model 00782 I just pop the sensor into the top small basket of the refrig ... close the top and monitor the temps from uP to 30 yards away. The disadvantage to this unit is that it only senses down to 0 degrees f. So there are other units that are wireless that may be better for you. However I have my refrig set to 40 degrees f and so I am satisfied with my sensor.